[y+√(x²+y²)]dx=xdy满足y(1)=0的解

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[y+√(x²+y²)]dx=xdy满足y(1)=0的解[y+√(x²+y²)]dx=xdy满足y(1)=0的解[y+√(x²+y²)]dx

[y+√(x²+y²)]dx=xdy满足y(1)=0的解
[y+√(x²+y²)]dx=xdy满足y(1)=0的解

[y+√(x²+y²)]dx=xdy满足y(1)=0的解
[y+√(x²+y²)]dx=xdy满足y(1)=0的解
dy/dx=[y+√(x²+y²)]/x=y/x+√[1+(y/x)²].(1)
令y/x=u,则y=ux,dy/dx=u+x(du/dx),代入(1)式得:u+x(du/dx)=u+√(1+u²),消去u即得:
x(du/dx)=√(1+u²),分离变量得:du/√(1+u²)=(dx)/x
积分之,得 ln[u+√(1+u²)]=lnx+lnC=ln(Cx)
故有u+√(1+u²)=Cx,将u=y/x代入即得:
y/x+√[1+(y/x)²]=Cx,于是得通解 y+√(x²+y²)=Cx²
将初始条件:x=1时y=0代入,即得C=1,故得特解为 y=x²-√(x²+y²)